Golf club heads often include a striking face insert that is attached to a main body of a golf club head, for example. Conventional unitary golf club heads typically include rigid metal striking faces that are often associated with a harsh feel on off-center shots, or increased weight compared to some multi-component golf club heads. But, to diminish unwanted vibrations, to increase discretionary weight, and/or to generally improve a golf club's performance by including a striking face that is of a harder or softer material than that of the main body, inserts of various materials may be used as the striking face of the golf club head.
A recent trend in golf club design has golf club manufacturers moving more mass from the center of the club head outward and rearward to increase moment of inertia. In iron type golf club heads, for example, this is often accomplished by forming perimeter-weighting elements located about a main (or rear) cavity. In some cases, even more mass is preferentially relocated by configuring the main, or rear, cavity to diverge in the forward direction, or by forming additional recesses that intersect with, and extend outward from, the main, or rear, cavity, e.g. forming an undercut recess.
However, divergence of the main, or rear, cavity proximate the heel portion creates a problem for club heads that include striking face inserts. Because such inserts must be secured to the striking face in a limited region, particularly when welded, the junction between the striking face insert and the remaining club head main body often becomes visible from the rear. This not only affects the golfer's confidence in his or her equipment, but also diminishes the ability to place a rear insert on the rear of the club head. For example, if the striking face insert is attached by a welding process, it is difficult to condition (e.g. by polishing, or selectively roughening) the surface of the club head proximate the weld area from the rear of the club head because the extension of the main, or rear, cavity is partially enclosed. This lack of polishing is not only aesthetically displeasing, but also makes it difficult to attach the rear insert.